try:
    from django.forms.utils import ErrorDict
except ImportError:
    from django.forms.util import ErrorDict  # type: ignore[no-redef, import-untyped] # noqa: E501

from django.utils.html import format_html

from .angular_base import NgFormBaseMixin, SafeTuple


class NgModelFormMixin(NgFormBaseMixin):
    """
    Add this NgModelFormMixin to every class derived from ``forms.Form``, if that custom ``Form``
    shall be managed through an Angular controller.
    It adds attributes ``ng-model``, and optionally ``ng-change``, ``ng-class`` and ``ng-style``
    to each of your input fields.
    If form validation fails, the ErrorDict is rewritten in a way, so that the Angular controller
    can access the error strings using the same key values as for its models.
    """  # noqa: E501

    add_djng_error = False

    def __init__(self, data=None, *args, **kwargs):
        self.scope_prefix = kwargs.pop(
            "scope_prefix",
            getattr(self, "scope_prefix", None),
        )
        self.ng_directives = {}
        for key in list(kwargs.keys()):
            if key.startswith("ng_"):
                fmtstr = kwargs.pop(key)
                self.ng_directives[key.replace("_", "-")] = fmtstr
        if hasattr(self, "Meta") and hasattr(self.Meta, "ng_models"):
            if not isinstance(getattr(self.Meta, "ng_models"), list):
                raise TypeError("Meta.ng_model is not of type list")
        elif "ng-model" not in self.ng_directives:
            self.ng_directives["ng-model"] = "%(model)s"
        self.prefix = kwargs.get("prefix")
        if self.prefix and data:
            if data.get(self.prefix):
                data = {
                    self.add_prefix(name): value
                    for (name, value) in data.get(self.prefix).items()
                }
            else:
                data = {
                    name: value
                    for (name, value) in data.items()
                    if name.startswith(self.prefix + ".")
                }
        super().__init__(data, *args, **kwargs)
        if self.scope_prefix == self.form_name:
            raise ValueError(
                "The form's name may not be identical with its scope_prefix",
            )

    def _post_clean(self):
        """
        Rewrite the error dictionary, so that its keys correspond to
        the model fields.
        """
        super()._post_clean()
        if self._errors and self.prefix:
            self._errors = ErrorDict(
                (self.add_prefix(name), value)
                for name, value in self._errors.items()
            )

    def get_initial_data(self):
        """
        Return a dictionary specifying the defaults for this form. This
        dictionary can be used to inject the initial values for an Angular
        controller using the directive:
        ``ng-init={{ thisform.get_initial_data|js|safe }}``.
        """
        data = {}
        ng_models = (
            hasattr(self, "Meta") and getattr(self.Meta, "ng_models", []) or []
        )
        for name, field in self.fields.items():
            if "ng-model" in self.ng_directives or name in ng_models:
                data[name] = (
                    self.initial.get(name) if self.initial else field.initial
                )
        return data

    def get_field_errors(self, field):
        errors = super().get_field_errors(field)
        if field.is_hidden:
            return errors
        identifier = format_html("{0}.{1}", self.form_name, field.html_name)
        errors.append(
            SafeTuple(
                (
                    identifier,
                    self.field_error_css_classes,
                    "$pristine",
                    "$message",
                    "invalid",
                    "$message",
                ),
            ),
        )
        return errors

    def non_field_errors(self):
        errors = super().non_field_errors()
        errors.append(
            SafeTuple(
                (
                    self.form_name,
                    self.form_error_css_classes,
                    "$pristine",
                    "$message",
                    "invalid",
                    "$message",
                ),
            ),
        )
        return errors

    def get_widget_attrs(self, bound_field):
        attrs = super().get_widget_attrs(bound_field)
        identifier = self.add_prefix(bound_field.name)
        ng = {
            "name": bound_field.name,
            "identifier": identifier,
            "model": ("%s['%s']" % (self.scope_prefix, identifier))
            if self.scope_prefix
            else identifier,
        }
        if hasattr(self, "Meta") and bound_field.name in getattr(
            self.Meta,
            "ng_models",
            [],
        ):
            attrs["ng-model"] = ng["model"]
        for key, fmtstr in self.ng_directives.items():
            attrs[key] = fmtstr % ng
        return attrs
